Drug abuse is associated with ca. 70% of the total and 50% of the female AIDS cases in Puerto Rico (PR). Drug abuse of cocaine in particular by pregnant women is recognized to cause severe and often permanent lesions in the placenta. A previous report described that the placenta in HIV infected women were often "leaky" and also that such leakiness directly associated with perinatal HIV transmission. Our subsequent survey of women who delivered at the Obstetrics ward of the Ponce Regional Hospital (Ponce, PR), however, indicated that the placental leakage was as prevalent among HIV negative women as in HIV infected women. We therefore propose to investigate if maternal drug abuse is directly associated with the placental leakage; which allows fetal infusion of maternal blood containing the virus. Maternal urine, pubic hair as well as neonatal meconium plugs will be analyzed by ELISA and GC/MS for illicit drugs in order to accurately document the drug use history of the women. It is anticipated that the placental leakage is significantly more prevalent among the women who used drugs during pregnancy. It is unclear, however, if there might be a significant difference in either (or both) the prevalence or the severity of the placenta leakage between those who used drugs only in early stages of pregnancy and those who used at time close to full gestation. Leakage of HIV contaminated maternal blood through the placenta would markedly increase the risk of perinatal infection. Recent studies have shown that AZT treatment of HIV infected, pregnant women significantly reduce the risk of perinatal HIV transmission. Our hypothesis predicts that the drug induced placental leakage may be directly implicated in those cases where maternal AZT treatment failed to prevent the viral transmission to their infants. Existing statistics clearly have shown that the risk of perinatal HIV transmission is significantly higher in drug using mothers than in non-users.